Received: 3 June 2020
Accepted: 13 January 2021
First Online: 27 January 2021
Ethics approval and consent to participate
: Ethical consent has been obtained from the responsible research Ethical Committee (Ethical Committee Salzburg, 415-E/2184/2.2017). All parents who agreed to participate in the study provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.